Self-crimped yarn and method of producing the same

ABSTRACT

A high bulk, self-crimped plied yarn for use in carpets is disclosed. The composite yarn includes at least two or more component yarn ends, of which at least one must be a prebulked filament yarn of a heat-shrinkable synthetic fiber, while the remaining ones are spun staple fiber yarns. The starting yarn ends are individually twisted in the same sense, although the magnitudes of the twists may be different, and are plied with a twist in the opposite sense. Upon exposure of the plied yarn to heat, the filament yarn component shrinks, but such shrinkage is restricted by the spun staple fiber yarn component. This results in the formation of a relatively large crimp or &#39;&#39;&#39;&#39;kink&#39;&#39;&#39;&#39; in the composite yarn which is then heat-set therein and imparts thereto bulk properties simulative of Murchie or stuffer box crimped yarns. The component yarns may have different dye affinities to permit production of multi-colored yarn. This abstract is not to be taken either as a complete exposition or as a limitation of the present invention, however, the full nature and extent of the invention being discernible only by reference to and from the entire disclosure.

United States Patent [191 Glowacki [451 Aug. 27, 1974 1 SELF-CRIMPED YARN AND METHOD OF [73] Assignee: Uniroyal, Inc., New York, NY.

[22] Filed: May 11, 1973 [21] Appl. No.: 359,523

Related US. Application Data [63] Continuation-impart of Ser. No. 215,014, Jan. 3,

1971, abandoned.

[52] US. Cl 57/140 BY, 57/157 R, 57/157 MS [51] Int. Cl D02g l/l8, D02g 3/04 [58] Field of Search... 57/34 R, 34 HS, 139, 140 R,

57/140 BY, 144, 156, 152, 160, 157 R, 157

TS, 157 MS [56] References Cited UNITED STATES PATENTS 2,575,753 11/1951 Foster 57/139 3,344,597 10/1967 Petree 57/140 BY X 3,375,655 4/1968 Swales....., 57/140 R 3,377,794 4/1969 Walker 57/157 MS 3,412,547 11/1968 Martin 57/152 3.438.193 4/1969 Kosaka et a1. 57/144 3,540,204 11/1970 Tanaka et a1. 57/152 UX Primary ExaminerDona1d E. Watkins Attorney, Agent, or FirmNorbert P. Holler, Esq.

[ ABSTRACT A high bulk, self-crimped plied yarn for use in carpets is disclosed. The composite yarn includes at least two or more component yarn ends, of which at least one must be a prebulked filament yarn of a heatshrinkable synthetic fiber, while the remaining ones are spun staple fiber yarns. The starting yarn ends are individually twisted in the same sense, although the magnitudes of the twists may be different, and are plied with a twist in the opposite sense. Upon exposure of the plied yarn to heat, the filament yarn component shrinks, but such shrinkage is restricted by the spun staple fiber yarn component. This results in the formation of a relatively large crimp or kink in the composite yarn which is then heat-set therein and imparts thereto bulk properties simulative of Murchie or stuffer box crimped yarns. The component yarns may have different dye affinities to permit production of multi-colored yarn. This abstract is not to be taken either as a complete exposition or as a limitation of the present invention, however, the full nature and extent of the invention being discernible only by reference to and from the entire disclosure.

14 Claims, 4 Drawing Figures SELF-CRIMPED YARN AND METHOD OF PRODUCING THE SAME This application is a continuation-in-part of my prior copending application Ser. No. 215,014, filed Jan. 3, 1971, and now abandoned.

The invention relates to high bulk plied yarns suitable for use in carpets, and more particularly to selfcrimped plied yarns of high bulk and methods of producing the same.

Most carpet yarn, i.e., yarn used in making the pile surfaces of commercial and residential carpeting, is of the type known as plied filament yarn and is composed of plied bundles of continuous filaments extending generally longitudinally of the yarn. Another type of carpet yarn is made of spun synthetic or natural staple fibers, i.e., fibers of finite lengths ranging generally from fractions of an inch up to several inches. All carpet yarns of either type, when first made, are normally characterized by low or no bulk and thus are subjected to a process or processes which can provide the desired higher bulk without seriously affecting the yarn quality. The bulk of the yarn is, of course, the quality which gives the carpet the sought after plush feeling.

Examples of carpet yarns that are offered commercially by the assignee of this application are filament nylon yarn and staple fiber nylon yarn. The filament yarns are preferably bulked by steam in variousways which are well known in the art, while the spun yarns are bulked by stuffer box crimping techniques following which the yarn is heat-set. The bulked carpet yarn is then rewound into appropriate packages for shipment to the customer.

Heretofore, attempts at providing bulk in the finished yarn as a function of the plying of the individual yarn ends have been made but have not been too successful. These attempts have usually involved the use of an unbalanced or differential twist, i.e., a low twist in the single ends and a high twist in the plied composite yarn. The use of such twist levels in the single ends and the ply has been found to create a torque in the yarn and give it some crimp, but practically no bulk has been achieved in this way.

It is an important object of this invention, therefore, to provide a novel carpet yarn that has high bulk.

It is also an object of the present invention to provide such a carpet yarn the construction of which enables it to self-crimping so that it can be bulked without use of mechanical crimping techniques.

Generally speaking, the objectives of the present invention are attained by providing at least one end of preferably prebulked continuous filament yarn of a heat-shrinkable synthetic textile fiber, e.g., nylon, polyester, polypropylene, and the like, and at least one end of spun staple fiber yarn. The yarn deniers should be between about 1,000 and about 5,000, with a denier of about 2,400 being preferred for the filament yarn and sired. The starting yarn ends are individually twisted in one direction, e.g. they are given a Z-twist between about 2.5 and about 7.0 turns per inch and preferably about 5.0 tpi. The degree of twist may be the same or difierent for the various yarn ends, but in the latter case the filament yarn twist should be the lower one and the difference preferably should not be greater than about 1.5 tpi. The several yarn ends are then plied with each other with an opposite twist, i.e., with an S-twist, the degree of twist being between about 0.5 and about 6.5 tpi and preferably about 4.25 tpi. Where an unbalanced twist is to be used, the ply twist should normally be ap-' proximately equal in magnitude to the lower of the twists previously imparted to the single ends. Since the ply twist is opposite to the singles twist, the component yarns end up with an almost zero twist (frequently reabout 7.5 minutes. The yarn is then subjected to steam at an appreciably higher pressure and temperature for an additional period of about 10.0 to about 20.0 minutes. During the entire heating period, but especially during the low pressure part of the cycle, the filament yarn component is subjected to shrinkage forces over its entire length. In the staple fiber yarn component, however, any shrinkage which can occur is limited to the individual, relatively short length fibers and is not synergistic, i.e., the shrinkage of any given fiber does not affect any adjacent fiber, so that the staple fiber yarn as a whole shrinks either not at all or only a minimal amount. The staple fiber yarn component thus acts to restrict the shrinkage of the filament yarn component and causes the composite yarn to increase in bulk by the development of relatively large crimps or kinks. The high bulk so produced is heat-set during the high pressure part of the cycle. Thereafter, the plied yarn is allowed to cool, dried and finally deskeined and rewound into a package ready for shipment.

The operation as described above is found highly suited for bulking nylon carpet yarn, and in its details may follow the procedures outlined in Technical Information Bulletin N-l85, titled Twist-Setting Carpet Yarns of DuPont Nylon, published by the Textile Fibers Department of E. I. DuPont de Nemours & Company, Inc. in March 1965. For fibers other than nylon, the procedure will be generally similar, although some of the individual operating parameters may vary in accordance with specifications normally furnished by the filament yarn manufacturers.

The foregoing and other objects, characteristics and advantages of the present invention will be more clearly understood from the following detailed description when read in conjunction with the accompanying drawing, in which:

FIG. 1 is a diagrammatic view, drawn to a greatly enlarged scale, of a filament yarn to be a component of a composite yarn according to the present invention;

FIG. 2 is a similar view of a spun stable fiber yarn to be a component of the composite yarn;

FIG. 3 is a similar view of the composite yarn of the invention prior to heat-setting; and

FIG. 4 is a similar view of the composite yarn after heat-setting.

Referring now to the drawing in greater detail, a filament yarn 10 is shown in FIG. 1 as having been pretwisted in the Z direction, denoted by the lines 11. A spun staple fiber yarn l2 similarly pretwisted in the Z direction, denoted by the lines 14, is shown in FIG. 2. The two component yarns are shown in FIG. 3 as having been plied with an opposite or S-twist. In the resultant composite yarn 15, each of the component yarns is, therefore, left with an approximately zero (as is) twist, due to the fact that the reverse twist substantially removes the initial singles twist.

Merely by way of example, one composite yarn which has been found particularly suitable for a selfcrimping treatment according to the present invention is characterized as including one end of 2600 denier 2/l spun nylon staple yarn with a 5.0 tpi Z-twist, plied at a 4.25 tpi S-twist with one end of 2400 denier filament nylon yarn having a 4.25 tpi Z-twist. Other combinations will, of course, be usable as well, for example, polypropylene filament or polyester filament with rayon, polypropylene, polyester or nylon staple, nylon filament with rayon, polyester or polypropylene staple, any of such filament yarns with natural fibers such as wool and cotton, and the like. Also, the filament and staple fiber yarn components may be possessed of different selective dye affinities, either by virtue of their inherent structural dissimilarities or by virtue of having been pretreated by suitable processing agents well known to the art, for example, as taught in US. Pat. No. 3,439,999, so as to enable the creation of a multicolor effect in the plied yarn by an appropriate dyeing operation.

The composite yarn is then skein ed and subjected for a predetermined time interval in a continuous operation first to a low-temperature and low-pressure humid steam atmosphere, and then to a high-temperature and high-pressure steam atmosphere, in an autoclave or other suitable steam chamber. The heat causes the filament yarn to develop shrinkage stresses over its entire length. At the same time, even if the spun yarn 12 is made up of heat-shrinkable staple fibers, any shrinkage in the same is limited to the individual fibers. As a result, the spun yarn tends to oppose the shrinkage of the filament yarn, which causes the composite yarn 15 to buckle and develop a crimp or kink denoted 16 in FIG. 4. The so-produced bulk is heat-set in the yarn. At the end, of the heating period, the skein is allowed to cool, dried, then rewound into packages for shipment.

It will be understood that the foregoing detailed description of the present invention is for purposes of illustration only, and that the various structural and operational features and relationships herein disclosed are susceptible to a number of modifications and changes none of which entails any departure from the spirit and scope of the present invention as defined in the hereto appended claims. Thus, the description has been couched primarily in terms of carpet yarn, but the principles of the invention may be applicable to bulking yarns for other purposes as well, such as for use in clothing, drapery, etc., even though for such purposes different twist levels and yarn deniers may be required.

What is claimed is:

l. A self-crimped composite yarn of high bulk, comprising a plurality of yarn ends at least one of which is a continuous filament yarn of a heat-shrinkable synthetic fiber and at least another of which is a spun staple fiber yarn, .each of said yarn ends having an individual twist imparted thereto in a direction which is the same for all said yarn ends, said yarn ends being plied to one another with a twist opposite in directon to that of said individually yarn ends, and the plied yarn being laterally crimped or kinked by thermally induced shrinkage of the continuous filament yarn component against the resistance to such shrinkage offered by the spun staple fiber yarn component, such crimps or kinks being heat-set in the plied yarn to define the bulk thereof.

2. A composite yarn according to claim 1, wherein the respective twists imparted to the individual yarn ends are each between about 2.5 and about 7.0 turns per inch, and the ply twist is between about 0.5 and about 6.5 turns per inch.

3. A composite yarn according to claim 1, wherein the twist imparted to each continuous filament yarn end is lower than the twist imparted to each spun staple fiber yarn end, and the ply twist is substantially equal to said lower twist.

4. A composite yarn according to claim 3, wherein the respective twists imparted to the individual yarn ends are each between about 2.5 and about 7.0 turns per inch, and the ply twist is between about 0.5 and about 6.5 turns per inch.

5. A composite yarn according to claim 4, wherein the plied yarn is constituted of one end of 2400 denier continuous filament nylon yarn having a twist of about 4.25 turns per inch Z and 1 end of 2600 denier 2/1 spun nylon staple fiber yarn having a twist of about 5.0 turns per inch Z, and the ply twist is about 4.25 turns per inch S.

6. A composite yarn according to claim 1, wherein the respective yarn components have different selective dye affinities to enable creation of a multi-color effect in the plied yarn by a subsequent dyeing treatment thereof.

7. The method of producing a self-crimped composite yam of high bulk, comprising the steps of providing at least one end of a continuous filament yarn of a heatshrinkable synthetic fiber and at least one end of spun staple fiber yarn, twisting all of said yarn ends individually in the same given direction, plying all said yarn ends with one another in a twist direction opposite to that of said individual yarn ends, and subjecting the resultant plied yarn to a thermal treatment to induce shrinkage stresses in the continuous filament yarn component, the resistance to shrinkage of said continuous filament yarn component offered by the spun staple fiber yarn component causing development of bulkdefining crimps or kinks in the plied yarn which are heat-set therein.

8. The method of claim 7, wherein the respective twists imparted to the individual yarn ends are each between about 2.5 and about 7.0 turns per inch, and the ply twist is between about 0.5 and about 6.5 turns per inch.

9. The method of claim 7, wherein the twist imparted to each continuous filament yarn end is lower than the twist imparted to each spun staple fiber yarn end, and the ply twist is substantially equal to said lower twist.

10. The method of claim 9, wherein the respective twists imparted to the individual yarn ends are each between about 2.5 and about 7.0 turns per inch, and the ply twist is between about 0.5 and about 6.5 turns per inch.

filament yarn component and said spun staple fiber yarn component have different selective dye affinities.

14. The method of claim 13, wherein the respective twists imparted to the individual yarn ends are each between about 2.5 and about 7.0 tums per inch, and the ply twist is between about 0.5 and about 6.5 turns per inch. 

1. A self-crimped composite yarn of high bulk, comprising a plurality of yarn ends at least one of which is a continuous filament yarn of a heat-shrinkable synthetic fiber and at least another of which is a spun staple fiber yarn, each of said yarn ends having an individual twist imparted thereto in a direction which is the same for all said yarn ends, said yarn ends being plied to one another with a twist opposite in directon to that of said individually yarn ends, and the plied yarn being laterally crimped or kinked by thermally induced shrinkage of the continuous filament yarn component against the resistance to such shrinkage offered by the spun staple fiber yarn component, such crimps or kinks being heat-set in the plied yarn to define the bulk thereof.
 2. A composite yarn according to claim 1, wherein the respective twists imparted to the individual yarn ends are each between about 2.5 and about 7.0 turns per inch, and the ply twist is between about 0.5 and about 6.5 turns per inch.
 3. A composite yarn according to claim 1, wherein the twist imparted to each continuous filament yarn end is lower than the twist imparted to each spun staple fiber yarn end, and the ply twist is substantially equal to said lower twist.
 4. A composite yarn according to claim 3, wherein the respective twists imparted to the individual yarn ends are each between about 2.5 and about 7.0 turns per inch, and the ply twist is between about 0.5 and about 6.5 turns per inch.
 5. A composite yarn according to claim 4, wherein the plied yarn is constituted of one end of 2400 denier continuous filament nylon yarn having a twist of about 4.25 turns per inch ''''Z'''' and 1 end of 2600 denier 2/1 spun nylon staple fiber yarn having a twist of about 5.0 turns per inch ''''Z'''', and the ply twist is about 4.25 turns per inch ''''S.''''
 6. A composite yarn according to claim 1, wherein the respective yarn components have different selective dye affinities to enable creation of a multi-color effect in the plied yarn by a subsequent dyeing treatment thereof.
 7. The method of producing a self-crimped composite yarn of high bulk, comprising the steps of providing at least one end of a continuous filament yarn of a heat-shrinkable synthetic fiber and at least one end of spun staple fiber yarn, twisting all of said yarn ends individually in the same given direction, plying all said yarn ends with one another in a twist direction opposite to that of said individual yarn ends, and subjecting the resultant plied yarn to a thermal treatment to induce shrinkage stresses in the continuous filament yarn component, the resistance to shrinkage of said continuous filament yarn component offered by the spun staple fiber yarn component causing development of bulk-defining crimps or kinks in the plied yarn which are heat-set therein.
 8. The method of claim 7, wherein the respective twists imparted to the individual yarn ends are each between about 2.5 and about 7.0 turns per inch, and the ply twist is between about 0.5 and about 6.5 turns per inch.
 9. The method of claim 7, wherein the twist imparted to each continuous filament yarn end is lower than the twist imparted to each spun staple fiber yarn end, and the ply twist is substantially equal to said lower twist.
 10. The method of claim 9, wherein the respective twists imparted to the individual yarn ends are each between about 2.5 and about 7.0 turns per inch, and the ply twist is between about 0.5 and about 6.5 turns per inch.
 11. The method of claim 7, wherein the plied yarn upon being formed is wound free of tension on a skein and subjected to said thermal treatment in that condition.
 12. The method of claim 11, wherein thE skeined plied yarn is tumbled in an atmosphere of low-temperature, low-pressure steam to develop the principal portion of the bulk, and is then subjected to an atmosphere of high-temperature, high-pressure steam.
 13. The method of claim 7, wherein said continuous filament yarn component and said spun staple fiber yarn component have different selective dye affinities.
 14. The method of claim 13, wherein the respective twists imparted to the individual yarn ends are each between about 2.5 and about 7.0 turns per inch, and the ply twist is between about 0.5 and about 6.5 turns per inch. 